Area guide · SM7
House Extensions in Banstead (SM7)
Weighing up an extension in Banstead? The village has a rare balance: a proper high street to walk to, chalk downland light and beech trees over everything, and avenues of 1930s detached houses whose plots were drawn generously enough to carry serious enlargement. Owners tend to stay for decades here, which makes extending rather than moving the obvious arithmetic. The green belt wraps the village, which frames the bigger schemes without stopping them, and the local stock suits exactly the work we specialise in: glazed kitchen-garden rears, hip-to-gable lofts and double-storey reworks, with full programmes that regularly reach whole-house scale. Applications go to Reigate and Banstead Borough Council, and we carry the whole journey, first sketch to final sign-off.
Live planning data
What Reigate and Banstead is approving
Banstead applications go to Reigate and Banstead Borough Council, and what succeeds here follows the logic of any well-kept village: additions that hold the avenue's rhythm, roofs that stay in the family of the originals, and double-storey proposals argued carefully on proportion and neighbour outlook.
The village's 1930s houses give applicants a head start. Their plots are wide, their building lines are consistent, and a design that respects the roofline and matches the brick detail reads as a natural evolution rather than an imposition. Where the green belt applies, the extension is measured against the original house, a calculation we unpack in our green belt guide, and where ambition outgrows the standard bands, the brief moves into luxury extensions territory.
Local knowledge
Banstead's streets, four ways
The downs-edge avenues. The best plots in the village run off the downs, where 1930s detached houses sit with long gardens and open light behind them. These are the addresses where a double-storey rework makes most sense: the plot carries it comfortably and the gain in usable space is transformative.
The High Street side. Closer to the village centre, houses trade garden depth for the walk to the shops. Side-return and single-storey rear extensions do the heavy lifting here, opening kitchens to the garden without crowding the boundary.
Against Banstead Downs. Where gardens back toward the downland itself, siting and landscaping decide the application as much as floorspace. Designs that hold a low rear line and keep the beech screen intact tend to be received well.
The 1930s detached generation. Across all of it, the same houses recur: bay fronts, hipped roofs, side garages ripe for conversion. Their lofts convert generously, and a hip-to-gable with rear dormer often adds two rooms for less than a rear extension.
Every street is different. That's the point.
We design to Banstead's stock and to what the council demonstrably approves — not to a template. A free site visit tells you what your house can take.
Get my free estimateHonest numbers
What an extension costs in Banstead in 2026
Ranges cover the complete build and exclude VAT, professional fees and kitchen fit-out:
| Extension type | Typical Banstead cost | On-site time | Usual planning route |
|---|---|---|---|
| Side-return extension | £45,000 to £85,000 | 2 to 3 months | Often permitted development |
| Single-storey rear | £55,000 to £115,000 | 3 to 4 months | Often permitted development |
| Kitchen extension (incl. mid-range kitchen) | £70,000 to £140,000 | 3 to 4 months | Often permitted development |
| Hip-to-gable loft + rear dormer | £65,000 to £115,000 | 6 to 10 weeks | Usually permitted development |
| Wrap-around extension | £90,000 to £175,000 | 4 to 6 months | Full application |
| Double-storey rework | £95,000 to £210,000 | 5 to 7 months | Full application |
Work to £3,200 to £5,000 per square metre depending on specification. The larger programmes are banded in the luxury extension cost guide; whatever the scale, the sequence is a free design visit first and a fixed, itemised quotation before you commit.
Permissions, handled
Planning in Banstead: the green belt, kept in proportion
The original-building test. On green belt plots the council weighs your addition against the house as first built. We establish how much allowance survives at your address and design inside it with room to spare.
Permitted development does real work here. Most avenue plots keep their standard rear and loft allowances, and anything built under PD is documented with a Lawful Development Certificate so the position is never in doubt.
Neighbours and boundaries. Consistent building lines mean overlooking arguments are usually easy to answer, and where boundary excavation engages the Party Wall Act, allow £1,000 to £2,500 per adjoining owner if surveyors are appointed.
The clock. Expect around eight weeks for a householder decision, with the application prepared, submitted and chased by us throughout. Larger or more sensitive schemes benefit from early conversations with officers, and we arrange those where they will genuinely help the case.
How it works
How it works
- Free design visit. We measure the plot, check your PD and green belt position, and give a realistic view of cost before anything is drawn.
- Design and drawings. A scheme that matches the avenue's character while reorganising the inside around modern family life.
- Planning, handled for you. Application drafted, lodged and steered through Reigate and Banstead to decision.
- Fixed-price build. One itemised figure agreed up front, then a tidy, well-run site through to completion.
Questions, answered
Banstead extension FAQs
Does the green belt stop big extensions in Banstead?
No, it frames them. The test is proportion against the original building, and the village's 1930s plots usually leave meaningful headroom. We confirm your allowance before designing so the application starts from solid ground.
What should I budget for an extension here?
Plan on £3,200 to £5,000 per square metre in 2026. Single-storey rears typically run £55,000 to £115,000, lofts £65,000 to £115,000 and double-storey reworks £95,000 to £210,000, excluding VAT and fees. Your quote is fixed and itemised.
Can I extend under permitted development?
On most Banstead plots, yes: the standard rear and loft allowances survive. We verify the position for your address and certificate all PD work so the paperwork protects you.
Which houses suit a double-storey rework?
The detached avenues off the downs are ideal: wide plots, consistent building lines and roof forms that accept a second storey gracefully. It is the single most transformative project in the village.
Who decides my application and how long does it take?
Reigate and Banstead Borough Council, normally within about eight weeks of validation. We manage every stage, including any conditions after approval.
Do you take on bigger programmes than a single extension?
Yes. Where owners combine extension, loft and full internal remodel, budgets reach £250,000 and beyond, and that scale of project is our core strength.
Nearby areas we cover
What clients say
Rated 5.0 on Google
“Used The Extension Company for a loft conversion on our semi detached in Barnet and couldn't be happier. They explained what was possible at the first visit, sorted the planning side, and gave a fixed price with no surprises at the end.…” read the full review
“Really impressed with the entire project. The side extension and conservatory have been finished to a very high standard and the team made the process straight forward and stress-free. It’s transformed the space and added so much value, would definitely recommend.”
“Brilliant experience with the extension company, transparent from the word go. Completed a double story extension for me and I couldn’t be more pleased. Thank you”
“I got the extension company to do a bathroom refurb for us a January they done a great job they managed to fit in a large shower as well as a bath”
Reviews shown word for word from our Google profile. Read all 8 reviews on Google
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